If I go on a cruise, I will take it all including D800 and Canon T2i and a few point and shoots

Wow! So not only two DSLRS but also
a few
p&S???

A kit like that, with spare batteries, chargers, filters, and other assorted accesories must weigh like 2 tons. I could never envisage to lug all that equipment around for any trip.

But to each his own
--
Fer

Again I am only talking specifically about cruises, like a Caribbean cruise, which we've gone several on. Have you been to one of these cruises? You are on a giant cruise ship. Your stuff is in your cabin, you just take what you need that day (or you can change it several times a day).